Pacratistatin (1) and narciclasine (2) are natural products that are highly active against many cancer cell lines including murine P388 and lymphocytic leukemia; human cancer cells pancreas BXPC-3, breast MCF-7, CNS SF-268, lung NCI-H460, colon KM20L2 and prostate DU145. Although the exact mode of action for pancratistatin remains unknown, narciclasine is believed to inhibit peptide bond formation in eukaryotic ribosomes. Lycoricidine (3) and 7-deoxypancratistatin (4) are significantly less active, than the corresponding C-7 hydroxylated compound. The reduced activity maybe due to the absence of the hydrogen bonded donor acceptor pair in the phenanthridone functionality.
